Resumen

VELAZQUEZ-ZAPATA, Juan Alberto  y  DAVILA-ORTIZ, Rodrigo. Comparing the climate change signal on a mexican basin’s hydrology evaluated with global and regional climate simulations. Ing. invest. y tecnol. [online]. 2018, vol.19, n.3, pp.355-365. ISSN 2594-0732.  https://doi.org/10.22201/fi.25940732e.2018.19n3.030.

This study compares the climate change signal (CCS) on hydrological indicators over an east central Mexican basin by using two 5-member ensemble climate simulations under the A2 emission scenario: a) the Canadian Regional Climate Model (CRCM) driven by the Canadian Global Model (CGC), hereinafter referred to as CRCM-CGC, and b) CGC simulations. The dynamically downscaled simulations generated from the regional climate model provide a higher resolution. However, both CGC and CRCM-CGC simulations are affected by systematic biases which were corrected before being used in a hydrological model. The bias corrected ensemble climate simulations were used to feed the hydrological model GR4J in order to obtain discharge simulations in a reference (19712000) and a future (2046-2065) period. Results show that, in the reference period, the CGC and CRCM-CGC simulations lead to a good representation of the hydrological annual cycle. Regarding the future period, climate simulations produce a decrease in streamflow and a change in the annual cycle. In particular, CRCM-CGC lead to a larger decrease on the selected indicators than CGC; for example, the median CCS on mean monthly streamflow is -48% and -59% for CGC and CRCM-CGC, respectively. Overall, the choice of CGC or CRCM-CGC yields to different CCS (similar direction but different magnitude) for the study basin. This aspect should be taken into account in the evaluation of climate change impact on water resources for those southern Mexican basins which are excluded from the CRCM and other regional climate models domain.

Palabras llave : Climate change impact; dynamical downscaling; hydrology.